Ignition and scavenging means for internal-combustion engines



F. K AHN.

IGNITION ANDSCAVENGING MEANS FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED APR-4,192I.

Patented Dec. 27, 1921..

2 SHEETS-SHEET I,

v vucwfoz Wed 1112x611 uwiwa F. KAHN.

IGNITION AND SCAVENGING MEANS FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED APR. 4, I921.

1,401,706, I Patented Dec. 27,1921.

2 SHEETSSHEET 2.

PAT oEFlcE.

FRED KAIHN, OF TONGA NOXIE, -KANSAS.

IGNITION AN D SGAVENQING MEANS FOlB, INTERNAL-COMBUSTIdN ENGINES.

Specification of Letters latent.

Application filed-April 4, 1921. Serial No. 458,444.

. scavenging means for internal combustion en "nes. I no object of the invention is to provide simple and effective means for keeping the spark gap terminals clean so as to insure reliable ignition of the compressed charges at all times. I I

Another object of theinvention is to provide means for eleaning the spark terminals and increasing the length of the spark, thus insuring positive ignition.

A still further object of the invention is' to provide means for cleaning the spark gap by means of a portion of the mixture, compressed to a higher degree than the body of the mixture, was to project a cleansingstream through the spark gap to clean the spark terminals and at the same time increase the length of the spark, the expanding stream presenting the mixture in better condition for ignition and insuring the dispersion of the sparkthroughout the mass of the body of the mixture to be ignited.

A still further object ofthe invention is to provide means whereby the sparking means as a whole willbe scavenged on the exhaust stroke of the engine. I

The invention consists of the features of construction, combination and arrangement of parts, hereinafter fully described and claimed, reference being had to the accompanying drawings, in which:

Figure 1 is a vertical section through an engine cylinder and piston embodying my invention, showing one form of construction which may be employed. I I

Fig. 2 is a view similar'to Fig. 1 showing another form of construction.

Fig. 3 is a sectional elevation of the form of spark plug disclosed in Fig. 2.

Fig. 4 is a side elevation of the same.

Fi 5 is a transverse section on line 55 of Flg. 3.

' Fig.6 is a bottom plan view of the spark ug; Referring to the drawings, 1- in Fig. 1

and 1 in Fig. 2 designate an engine cylinder having a piston 2 operating therein. In Fi -1 I have shown the cylinder .1 provi ed with a'water jacket 3 having a head portion 4 which incloses the head of the cylinder. Fig. 2' shows a construction of cylinder 1 which may be used with or without a water jacket, that is, either in connection with a water cooled or an air cooled engine, and which further difi'ers struc- Patented Dec; 27, 1921..

turally from the cylinder shown in Fig. 1

as hereinafter fully described.

As shown in Fig. 1, the cylinder 1 is provided in its head portion with a socket or passage 5 for the reception of a spark plug 6. This plug 6 includes the core 7, central electrode 8, outer .casing or shell 9 and clamping nut 10, the parts being suitably constructed for use in any ordinary orpreferred type of ignition system. The spark plug 6 employed in connection with the cylinder 1, is generally similar in construction to the spark plug 6*- employed in connection with the cylinder. 1!, and the same referenc characters are used to designate corre sponding parts thereof. The sp arkplug 6 has its casing made of such length as to bridge the'water jacket space 4 and extend into the combustion chamber 11 of them.- gine, the casing of said spark plug 6 being threaded at its outer end to engage the outer threaded wall of said "socket or passage, as indicated at 12. In Fig. 2 the base ofthe spark plug extends through a passage 5 formed in the upper head of the cylinder, and. said passage and the-base of the spark plug are threaded for cated at 12. I The spark plug casing has a bottom wall closed except for the formation of a spark gap passage 13 therein. This passage is preferably of tapered form andreceives the pointed end of the electrode 8, the wall of the passage and end of the electrode 8 forming the spark gap terminals between which the spark is formed and which are to be kept clear of carbon or other deposits. The electrode 8 is spaced from the body wall of the casing 9 and is formed at a point above the passage 13 with an annular series of inlet openings or slots 14, so arranged that when the spark lplug is threaded into the passage 5 or 5 at ast one of the openings 14 therein will register with a' constricted port 15 formed in the cylinder head.

engagement as indi- In the form of my invention shown in i Fig. 1 the cylinder is provided with a small auxiliary cylinder or compression chamber 16 which is mainly arranged within the water space 4 so as to becooled thereby and terminates at its lower open end substantially flush with the top wall of the combustion chamber 11, said auxiliary cylinder orchamber 16 communicating at its upper end. with the passage 15; and a plunger or auxiliary piston 17 is provided upon the main piston 2 to enter said cylinder 16. In the form of my invention shown in Fig. 2 the auxiliary cylinder 16 is formed upon the top wall of the cylinder and depends into the combustion chamber 11 and is adapted to receive a plunger or auxiliary piston 17 on the main piston 2" operating in said cylinder. The piston 17 and 17 are preferably made hollow and communicate with the air space on the interior of the piston so that said auxiliary piston will be kept comparatively cool and from being overheated.

It will be observed that the port 15 provides a constricted passage between the auxiliary compression chamber or cylinder and the spark plug shell ofr casing for the reception of a portion of the fluid contents from the explosion chamber portion of the main cylinder, and that on the outstroke of the main piston the auxiliary piston or plunger 17 or 17 a will enter such auxiliary compression chamber or cylinder and force the fluid contained therein through the passage 15 into the spark plug shell or casing, from which it will be forced back into the main cylinder in the form ofa stream or jet through the spark gap or opening 13. Thus it will be understood that on the compression stroke of the main piston a portion of the fluid mixture will be received in the chamber 16 or 16 and compressed by theauxiliary piston 17 or 17 to a higher pressure than the body of the mixture in the explosion chamber 11, and that the pressure of the portion of the/charge contained in the auxiliary cylinder will be increased to a still greater degree on its flow through the ports 15 and 14 and the gap opening 13, with the result that it will be forced in the form of a jet or stream of high velocity through the gap 13, thus blowing and carrying away any deposits which may have been made on the spark terminals with the result that such spark terminals will be cleansed. On passing through the gap opening 13 into explosion chamber 11, the highly compressed stream will expand throughout the mass of the mixture under lower pressure in said explosion chamber. A further effect of the flow of the jet or steam of the highly compressed mixture through the gap 13 is to cause a prolongation of the spark, which will be carried throughout the mixture and extensively transmitted throughout the entire area of the body of fuel in the chamonroe ber 11, resulting in the instant explosion of the fuel charge acting on the piston 2 or 2 to impel it on its wonking stroke. An advantage of the compression of the charge in the chamber 16 or 16 is that the particles of the fuel mixture are more thoroughly combined and condensed and prepared for subsequent rarefaotion and expansion on passing through the gap 13, so as to provide a portion of the fuel mixture which will bemore readily and quickly united than the mass of the mixture and more quickly expanded, and which will therefore transfer its head to the body of the fuel mixture in the chamber 11, carrying with it a prolonged spark and a mass of flame which will be distributed throughout the entire area of the chamber 11. As a result the spark terminals will not only be cleansed, but a longer and more eflicient spark produced, and at the same time an instantaneous ignition of the compressed fuel mixture in the main cylin the fuel mixture, so that a working stroke of greater power will be obtained with a reduction of cartoon or other deposits. Again, on theexhaust stroke of the piston ,the spent gases will be forced through the -spark plug and gap and give a further cleanslng e ect, the result being that the sparking means will at all times be kept in a thoroughly clean and reliable working condition, greater power obtained, and a greater scavenging eflect secured.

Having thus fully described my invention, I claim:

1. In an internal combustion engine, a cylinder having an auxiliary compression chamber,aspark plug having a casing forming a ground electrode and provided with a fuel municating with said compression chamber,-

and the second electrode entering said fuel outlet, and means upon the cylinder piston to enter said compression chamber and force fluid from said chamber into and through said spark plug.

2. In an internal combustion engine, a main cylinder having a main compression and explosion chamber and a small auxiliary compression chamber communcating therewith, a spark plug having a fluid inlet communicating with said auxiliary compression chamber and a fluid outlet communicating with said main compression and explosion chamber, said plug also having a main elec trode terminating in said outlet and forming with the walls thereof spark terminals, and a main piston provided with a projection to enter said auxiliary compression chamber and compress and force fluid therefrom into and through said spark plug.

3. In an internal combustion englne, a

cylinder havin a main compression and explosion cham er, a small auxillary compression chamber formed integral with the head of said cylinder and communicating with said main compression and explosion chamber, a spark plug including a central electrode and a ground electrode casing, the latter having an inlet communicating through a restricted passage with the auxiliar compressionchamber and an outlet receiving the terminal of the central electrode, and a main piston provided with a projection to enter said auxiliary compression chamber and compress and force fluid therefrom into and through the spark plug casing.

4;. In an internal combustion engine, a main cylinder having a main compression and explosion chamber, a small auxiliary compression chamber communicatin at its inner end with the first-named cham er and having at its outer end a constricted feed port, a spark plug includinga central electrode and a ground electrode, the latterer comprising a casing 3 having an inlet commuicating "with said feed port and an outlet receiving the terminal of the central electrode, and a main piston operating in the main cylinder and provided with a projection to enter said auxiliary compression chamber.

5. In an internal combustion engine, a mam cylinder having amain compression and explosion chamber and a water jacket, the latter inclosing the head of said cylinder, a small auxiliary compression chamber formed upon the head of the main cylinder and surrounded by the head portion of the water jacket thereof, said auxiliary compression cylinder communicating at its inner end with the main cylinder and having a constricted outlet at its outer end, a spark plug having a central electrode and a ground electrode comprising a casing having an inlet communicating with the outlet of the auxiliary compression chamber and having in its'base a fluid outlet receiv-' ing the terminal of the central electrode and communicating with the compression chamber of the main cylinder, and a main piston operating in the main cylinder I and having a pro ection to enter said auxiliary compression chamber.

In testimony whereof I afiix my signature. FRED KAHN. 

